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{{#Wiki_filter:~CATEGORY3yREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9904090149DOC.DATE:99/04/07NOTARIZED:NOFACIL:50-389St.LuciePlant,Unit2,FloridaPowerSLightCo.AUTH.N9ME.AUTHORAFFILIATIONMADDEN,G.R.FloridaPower6LightCo.STALL,J.A.FloridaPower&:LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKET05000389 | |||
==SUBJECT:== | |||
LER99-002-00:on990311,SGECTerrorcausesoperationwithconditionprohibitedbyTS.Causedbydeficienciesindataanalysis'guidelineinstructions.Licenseewillchangedataanalysisguidelinesforleadanalysts.With990407ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENTIDCODE/NAMEPD2-3PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DRCH/HOHBNRR/DRPM/PECBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOOREiWNRCPDRCOPIESLTTRENCL11111'1111,11111111RECIPIENTIDCODE/NAMEGLEAVES,WAEODSPD/RABLECENTNRRDRCHHQMBNRR/DSSA/SPLBRGN2FILE01LMITCOMARSHALLNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL112211111111111111D0NNOTETOALLnRIDS>iRECIPIENTSPLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPZESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR19ENCL19 FloridaPower&LightCompany.6351S.OceanOrive,JensenBeach,FL34957~FPtApril7,1999L-99-8610CFR$50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit2DocketNo.50-389ReportableEvent:1999-002-00DateofEvent:March11,1999SGECTErrorCausesOperationwithaConditionProhibitedbTechnicalSeciftcationsTheattachedLicenseeEventReport1999-002isbeingsubmittedpursuanttotherequirementsof10CFR$50.73toprovidenotificationofthesubjectevent.Verytrulyyours,J.A.StallSiteVicePresidentSt.LucieNuclearPlantJAS/EJW/GRMAttachmentcc:RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LucieNuclearPlant9904090149990407PDRADQCK05000389SPDRanFPLGroupcompany NRCFORM366(6-1996)U.S.NUCLEARREGULATORYCOMMISSIONjLICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDBYOMBNO.3150.0104EXPIRES06/30/2001Estimatedburdenperresponsetocomplywithlhismandatoryinformationcollectionrequest:50hrs.ReportedlessonsloomedareincorporatedIntolhelicensingprocessandfedbacktoIndustry.FonrrardcommentsregardingburdenestimateloIheRecordsManagementBmnch(TAF33),U.S.NuckrarRegulatoryCommission,Washington,)3C205554001~andtothePaperwrxkReductionProioct(31500104j,OfficeofManagementandBudget,Washington,Dc20503.IfanfnfonnalioncollectiondoesnotdispbryacurrentlyvalidOMBcontrolnumber,theNRCmaynolconductorsponsor,andapersonisnotrequiredtorespondlo,IheInformationcollection.FACILITYNAME(1ISt.LucieUnit2DOCKETNUMBER(2)05000389PAGE(3)Page1of6TITLE(4)SGECTErrorCausesOperationwithaConditionProhibitedbyTechnicalSpecificationsEVENTDATE(5MONTHOAYYEARLERNUMBER6lSEQUENTIALREVISIONNUMBERNUMBERREPORTDATE(7)MONTHDAYFACILITYNAMEYEAROTHERFACILITIESINVOLVED(BlOOCKETNUMBER031119991999-002-00,0407FACILITYNAME1999OOCKE'rNUMBEROPERATINGMDDE(9)POWERLEVEL(10)100THISREPORTISSUBMITTEDPURSUANTTOTHEREQ20.2203(a)(2l(v)20.2203(a)(3)(i)20.2201(b)20.2203(sl(1)X50.73(a)(2)(i)50.73(a)(2)(u)20.2203(a)(2)(i)20.2203(a)(2)(ii)20.2203(a)(3)(u)20.2203(a)(4)50.73(a)(2)(iii)50.73(BH2)(iv)UIREMENTSOF10CFR%t(Checkoneormore)(11)50.73(s)(2)(vin)50.73(a)(2)(x)73.71OTHER20.2203(sl(2)(iii)20.2203(a)(2)(iv)50.36(c)(1)50.36(c)(2)50.73(a)(2)(v)50.73(a)(2)(vii)SpecifyinAbstractbeloworInNACForm366ANAMELICENSEECONTACTFORTHISLER(12)TELEPHONENUMBERSneIIereArseCedetGeorgeR.Madden(561}467-7155COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT13)CAUSESYSTEMCOMPONENTMANVFACTVAEAREPORTABLETOEPIXCAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETOEPIXSUPPLEMENTALREPORTEXPECTED(14IYES(I(Yes,completeEXPECTEDSUBMISSIONDATE).evIntaXNoEXPECTEDSUBMISSIONDATE(15)MONTHDAYABSTRACT/limitto1400spaces,/.e.,approximately15single.spacedtypewrittenlines/(16)DuringtheSt.LucieUnit2refuelingoutage11(SL2-11}steamgeneratorinspectioninNovember1998,thetubeatRow49Line85insteamgenerator(SG}2Bwaspluggedduetoawear-inducedindicationthatpenetrated47%throughwall,exceedingtheplugginglimitofTechnicalSpecification4.4.5.4.a.6.Uponreviewofhistoricaldata,itwasdeterminedthatthisindicationwaspresent,butnotidentifiedduringtheSL2-9andSL2-10examinations,andthatthedepthofthei.ndicationwasessentiallyunchangedduringthisperiodofoperation.Therefore,thistubeexceededtheplugginglimit,butremainedinserviceduringoperatingcycles9and10.DetectionandsubsequentpluggingofthistubeindicationresultedfromimprovementsinthedataanalysisandcontrolsimplementedfortheSL2-11inspection.LeadanalystsdidnotinformFPLthatthisindicationwasnotidentifiedduringthepriorexaminations.Themisseddetectionwasidentifiedduringthepostoutagereviewacti.vities.Correctiveactionsinclude:changingdataanalysisguidelinesforleadanalyststoreportconditionstoFPLthatmayindicatearepairabledegradationwasnotreportedinapriorexamination;modifyingdataanalysisguidelinesforwear-induceddegradationtoincludeinstructionstoscreenthe100kHzdifferentialand100kHzabsolutechannelsinadditiontothe400/100kHzdifferenti.almixchannel,andreportflaw-likeindications;andincludingthewearindicationsthatwereidentifiedduringtheSL2-11inspections,butnotreportedinSL2-10inspections,inthetrainingandtestingofdataanalysispersonnel.NACFORM366I6.1996) | |||
NRCFORM366A(8-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)St.LucieUnit2~DOCKETNUMBERI2)05000389LERNUMBERI6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGEI3)Page2of6TEXT(Ifmorespeceisrequired,useadditionelcopiesofNRCFarm366A)I17)EventDescriptionOnMarch11,1999,apostoutagereviewofthesteamgenerator(SG)[EIIS:AB:SG)tubedegradationtrendswasbeingpreparedforthefall1998refuelingoutage(SL2-11)steamgeneratorexaminationreport.Itwasnotedthatawear-inducedindicationinthetubeatRow49Line85ofSG2Bwasreportedas47%throughwallanddidnotshowanyevidenceofgrowthbasedoncomparisontotheSL2-10examinationdata.ThistubewaspluggedduringtheSL2-lloutage.ThisreviewconfirmedthatthisindicationwaspresentintheSL2-10examinationdata,andmeasuredapproximatelythesamedepth,butwasnotreported.Althoughtheleadreviewteam(LRT)analysts(contractors)hadmadethissamedeterminationduringtheSL2-11examination,itwasnotbroughttotheattentionoftheFPLrepresentative.AmoreextensivereviewonMarch12,1999determinedthattheindicationwasalsopresentintheSL2-7,SL2-8andSL2-9examinationdataandwasnotreportedbyeithertheprimaryorsecondaryanalysts(contractor).Thisreviewshowedthattheindicationdidnotexceedtheplugginglimit(40%.throughwall)ofplantTechnicalSpecificationsuntiltheSL2-9andlaterexaminations.IntheSL2-11examination,theindicationwasnotreportedbytheprimaryanalyst(contractor),butwasidentifiedbythesecondaryanalyst(contractor)throughtheuseofacomputerdatascreeningsystem(CDS).TheCDSsystemusespre-establishedscreeningparametersthatarequalifiedtodetectdegradationthatisknownorpostulatedtoexistintheSGs.DuringtheSL2-11examination,theCDSsystemparameterswereenhanced"toscreenforpotentialfree-spancracking,whichhasbeenreportedduringprevious'examinationsintheSt.LucieUnit1(originalSGs),SONGS,andCalvertCliffsSGs.Theenhancedscreeningparametersusedforfree-spancrackingoverlappedthesameregionofthetubebundleinwhichthediagonalsupportwear-inducedindicationsoccur,andresultedindetectionofthewear-inducedindicationthatpreviouslywasnotreported.CauseoftheEventAbarrieranalysiswascompletedtodeterminethecausesthatcontributedtothisevent.ThecausesfornotreportingtheindicationintheSL2-10examinationweredeterminedtobe;1)deficienciesindataanalysisguidelineinstructions,and2)inadequatedataanalysttraining.Inaddition,thedataanalysisguidelinedidnotinstructleadanalysts(contractor)toreportconditionstoFPLthatmayindicatethatarepairabledegradationwasnotreportedinpriorexaminations.Thiswouldprovideearlieridentificationofpotentialproblems.AreviewofindustryqualifiedexaminationtechniquesprovidedthroughEPRIshowsthat,forwear-inducedindications,screeningofthe400/100Khzdifferentialmixchannelisoneofseveralacceptabletechniques.Latitudeisgivenfortheusertospecifyadditionalchannelstobescreenedforconfirmationandtoprovideadditionalinstructions.ThisinformationhasbeensharedwithEPRIfortheirreview.Withtheexceptionoftheaddedinstructionstoscreenthe100Khzdifferentialchannelforfree-spancrackinginSL2-11,thedataanalysisguidelineintheSL2-10andSL2-llexaminationswereidenticalwithrespecttothescreeningandreportingofwear-inducedindications.Theguidelinerequiresthattheindicationappearflaw-likeonthe400/100kHzdifferentialmixchannel,oronthe100kHzabsolutechannel.AreviewofSL2-11datashowsthisindicationmaintainsflaw-likecharacteristicsconsideredtypicalofwear-induceddegradationonthe100Khzdifferentialand100Khzabsolutechannels,butdoesnotmaintaintheminthe400/100KhzdifferentialmixNRCFORM388AI8.1998) | |||
NRCFORM366A(6-I998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)St.LucieUpit2OOCKETNUMBERI2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUM8ERNUMBER1999-002-00PAGEI3)Page3of6TEXTfifmorespaceisrequired,useedditionelcopiesofNRCForm366A)I17)channel.Theapparentlackofflaw-likecharacteristicsinthe400/100Khzdifferentialmixchannelmaybeattributabletoalongerandmoregradualtaperassociatedwithsomediagonalsupportwear-inducedindications.Thiswouldexplainthelackofflaw-likecharacteristicsinthe400/100Khzdifferentialmixchannel,andprovideanexplanationwhytheindicationwasnotreportedduringpreviousexaminations.Theguidelinedoesprovidelatitudetoreportindicationsnotspecificallyaddressedordescribedwithintheguideline(Section15.8),yettheindicationremainedunreported.Xnretrospect,theguidelineshouldrequiredataanalysispersonneltoreportsuspectedwear-inducedindicationsifanyoftheabovechannelsappearflaw-like.Thislogicshouldbeappliedtobothprimaryandsecondaryanalysisreviews.Theindividualanalysts(contractor)thatreviewedthedataforthisindicationhadpreviousSt.LucieUnit2experienceaswellassimilarplantexperience,andarefromreputableorganizations.Furthermore,theirperformancedemonstrationtestresultsdonotindicateaproblemwithdetectionorreportingofwear-inducedindications.Also,dataanalysts(contractor)aretypicallylimitedto8-10hourshiftstoreducefatigue.Nospecificexaminationdate,vendororganization,orworkshiftcanbeidentifiedasasignificantcontributortothisevent.Thissupportstheconclusionthatpotentialinadequaciesexistintheinstructionsprovidedinthedataanalysisguideline,andthesitespecifictrainingandtestingofdataanalysispersonnelforreportingofwear-inducedindications,ratherthaninpersonnelorequipmentrelatedissues.ThecurrentguidelinedoesnotspecificallyprompttheleadreviewanalyststoreportconditionstoFPLthatmayindicatethatarepairabledegradationwasnotpreviouslyreportedinapriorexamination.Althoughthiswouldnothaveeliminatedthefactthattheindicationwasnotreported,itdiddelaytheevaluationofpotentialproblems.Thisagainappearstobeanoversightinthedataanalysisguidelineinstructions.AnalysisofSGexaminationdataisperformedinaccordancewithwritteninstructionsandprotocolthatareprovidedinFPLdataanalysisguidelines.Priortoeachexamination,dataanalysispersonnel(contractor)areindoctrinated,trained,andtestedtodemonstrateproficiencyinapplicationofguidelineinstructions.DataanalysispersonnelarealsorequiredtopassanHPRIstandardizedtrainingandtestingprogramforQualifiedDataAnalyst.ThedataanalysisprocessatFPLincorporatesindependentprimaryandsecondaryanalysesforalldataacquired.Secondaryanalysis.utilizescomputerdatascreening(CDS)methodstoprovideaddedassurancethatallindicationsarereported.Ateamofresolutionanalysts(contractor)dispositionsdifferencesbetweenprimaryandsecondaryanalyses.Leadreviewteams(LRT)(contractor)reviewtheresolutionteamoutputforconsistencyinapplicationofguidelineinstructions,selectindicationsfordiagnosticexaminations,selectin-situtestingcandidatesandprovidefinalinputtothetubeplugginglist.Inadditiontoroutineanalysisasdiscussedabove,reviewsarecompletedtoevaluategrowthtrends,assessdetectionperformance,providedataanalystfeedback,andensurethatallindicationsreportedinapriorexaminationareaddressedinthecurrentexamination.Theleadreviewanalysts(contractor)areinstructedtousehistoricaldatatoevaluatecurrentoutageresults.Thisistypicallyaccomplishedusingthedatasegmentrecall(DSR)functionprovidedintheanalysissoftware,orbyuseofrawdataavailableonopticaldisksorharddrives.DSRisthefirstcourseofNRCFORM3BBAIB.1998) | |||
NRCFORM366A(81998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBERI2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGEI3)Page4of6TEXT(Ifmorespeceisrequired,useedditionalcopiesofNRCForm366AJ(17)actionsinceallindicationsreportedinthepriorexaminationshouldbeavailableinthisformat.Thealternativeistherawdataondisk.TheabsenceofaflawhistoryonDSRforanindicationcouldbeusedtoinitiatefurtherevaluationstodetermineiftheindicationwaspresent,butnotreportedinthepreviousexamination,andifitappearedtoexceedthetube-plugginglimit.Thisinturnshouldalertleadpersonnel(contractor)toinformtheFPLrepresentative.Currentscreeninginstructionsinthedataanalysisguidelinehaveidentifiedmorethan500tubesthatareaffectedbywear-induceddegradation,whichistypicalforthesteamgeneratordesigninstalledatSt.LucieUnit2.Currentinstructions,however,donotaccountforindicationsthatlackflaw-likecharacteristicsinthe400/100kHzdifferentialmixchannel,butmaintainflaw-likecharacteristicsinthe100kHzdifferentialor100kHzabsolutechannels.Areviewofindicationsthathaveremainedunreportedinpriorexaminationsshowsthatonlyoneindication(Row49Line85inSG2B)hasexceededthetube-plugginglimitofPlantTechnicalSpecificationsduringpreviousoperation.Theadditionalscreeningrequirementsimplementedforfree-spancrackingappeartobeeffectiveinreportingthisformofwear-induceddegradation,andshouldberequiredintheanalysisinstructions.Znaddition,dataanalysisguidelinesshouldbemodifiedtoinstructleadanalystpersonneltoreportconditionstoFPLthatmayindicatethatrepairabledegradationisnotbeingreportedinpriorexaminations.Dataanalysttrainingandtestingshouldalsoberevisedtoincludewear-inducedindicationsthathavenotbeenreportedinpriorexaminations.AnalysisoftheEventThiseventisreportableunder10CFR50.73(a)(2)(i)(B)asanyoperationorconditionprohibitedbytheTechnicalSpecifications(TS).TS3.4.5statesthateachsteamgeneratorshallbeoperable.TheapplicableACTIONstatementstatesthatwithoneormoresteamgeneratorsinoperablerestoretheinoperablesteamgeneratortooperablestatuspriortoincreasingT,above200'F.TSSurveillance4.4.5.0statesthateachsteamgeneratorshallbedemonstratedoperablebyperformanceoftherequired'ugmentedinserviceinspectionprogram.TS4.4.5.4.a.6PluggingLimitmeanstheimperfectiondepthatorbeyondwhichthetubeshallberemovedfromserviceandisequalto40%ofthenominaltubewallthickness.TS4.4.5.4.a.7statesthatatubeisunserviceableifitleaksorcontainsadefectlargeenoughtoaffectitsstructuralintegrityintheeventofanoperating-basis-earthquake(OBE),aloss-of-coolant-accident(LOCA),orasteamli.neorfeedwaterlinebreak.Contrarytotheabove,onMarch12,1999,FPLidentifiedthatSG2Boperatedthroughoutoperatingcycle9and10withthetubeatRow45Line85havinga47%throughwallwearindication.SafetySignificanceThesteamgeneratortubesaredescribedinUFSARsection5.4.2.1.3.Thetubesaredesignedtoallowforwallthinningandthegeneratorsaredesignedtominimizethepotentialfordenting.TheUFSARdiscussesconsiderationsforlocalizedcorrosionleadingtotubedegradation,whichisthepredominantdegradationmechanismseenintheindustry.St.LucieUnit2DesignBasisDocument,Volume9,discussesreactorcoolantsystemintegrity.Etalsodiscussesthestructuralintegrityrequirementsforsteamgeneratortubes,andprovidesanassessmentofmaximumallowabletubewallNAGFOAM366A181998) | |||
NRCFORM366A(8.1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBER(2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGE(31Page5of6TEXTfifmorospaceisrequired,usoadditionalcopiesofNRCForm368A)(171degradationthatcansustaintheloadingimposedbynormaloperationandpostulatedaccidentconditions.Thisshowsthatamaximumallowabletubewalldegradationof63%iswithinthedesignbasisforthesteamgeneratortubing.MechanicalwearintheUnit2steamgeneratorsisaresultofadesignflawinthefabricationoftheunits.ThedesignflawwasdiscoveredfollowingaprimarytosecondaryleakatanotherplantandatSt.LucieUnit2duringCycle2shortlythereafter.InthetubeleakeventatSt.Lucie2,theleakagewaslimitedtoapproximately20gallonsperday(gpd).Airejectormonitorsreadilydetectedit,andtheunitwasshutdownwithinafewdays.ThehistoricaltubeleaksatSONGSUnit2andSt.LucieUnit2occurredinaregionofthetubebundlethatwasanalyzedtobesusceptibletorapidgrowthrates.PreventativetubepluggingwascompletedatSt.LucieUnit2toremovethesusceptibletubesfromservice~Therefore,itiscurrentlyunlikelythatweardegradationwouldresultinthroughwallpenetrationandprimarytosecondaryleakageinoneortwocyclesofoperation.Extensiveinspectionshavebeencompletedateachrefuelingoutagesincethattime,andtherateofwearhasbeenlow.Afterimplementationofpreventivepluggingmeasures,itwasnotexpectedthattherateofwear-induceddamagewouldresultinathroughwallpenetrationafteroneortwocyclesofoperation.Furthermore,thepotentialeffectsassociatedwithathroughwallpenetrationscenariohavebeenshowntohavenoeffectonsafety.Adesignbasissteamgeneratortuberupture(SGTR)accident,asdescribedinChapter15oftheSt.LucieUFSAR,isdefinedasadouble-endedguillotinebreakofatubethatresultsininitialprimarytosecondaryleakratesinexcessof300GPM.ABB/CEhasperformedprototypicallaboratorytestingtoempiricallydeterminetheleakratefromtubedefectsthatwereintendedtosimulateweardefects,producebytubesupports.Thesetestsshowed"thatinallcases,whenwear-initiateddegradationislesqthanthestructurallimitofthetubing,primarytosecondaryleakagewouldnotbeexpectedtooccurundernormaloperationorpostulatedaccidentconditions.Eveninthemajorityofcaseswhensuchdegradationexceedsthestructurallimit,athroughwallpenetrationofthistypewillresultinaleakratelessthanoneGPM,andwouldnotsuddenlyleakinanuncontrolledmanner.ThesetestresultshavebeenfurthersubstantiatedbytheslowsteadyleakratesthatoccurredduringearlyoperationfromthroughwallpenetrationsintheSONGSUnit2andSt.LucieUnit2steamgenerators.Therefore,'heleakratesthatcouldresultfromweardefectswouldbewithinthecurrentTechnicalSpecificationlimitsoftheunitandwould,therefore,representanoperationalconcernbutnotasafetyconcern.Asaresult,potentialtubedefectsfrommechanicalweararenotconsideredasapossibleinitiatingeventofaSGTRaccidentbut,rather,asapotentialincreaseinthenormalsecondarysystemradionuclideinventorythatisusedasaninitialconditionforotherChapter15accidentanalyses'econdarysystemradionuclideinventoriesassumedintheUFSARChapter15safetyanalysisarebasedononepercentfailedfuelandacontinuousoneGPMprimarytosecondaryleakrate.Asdiscussedabove,themostsevereleakratesassociatedwithtypicalthroughwallwearpenetrationsaretypicallymuchlessthanoneGPM.Inaddition,operationwithonepercentfailedfuelisconsideredhighlyunlikely.Hence,actualsecondarysystemradionuclideinventoriesareexpectedtobemuchlessthanthoseassumedintheaccidentanalysis.Asaresult,theradiologicalconsequencesassociatedwithpostulatedwear-inducedtubeleakagewillbeboundedbythoseaccidentscurrentlydescribedinChapter15oftheUFSAR.NRCFORM309A(9.1998) 0 NRCFORM3BBAIB.I990)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBER(2I05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGE(3)Page6of6TEXTilfmorospecersrequired,useedditionelcopiesoflVRCForm3S6A)(17)ItshouldalsobenotedthatoperationwithacontinuousoneGPMprimarytosecondaryleakrateisanunrealisticassumption.TheSt.Lucie2TechnicalSpecificationsdonotpermitoperation'ftotalprimarytosecondaryleakageexceedsoneGPMthroughallsteamgenerators,orifleakagefromanyonesteamgeneratorexceeds720gallonsperday(0.5GPM).StLucieperformsprimarysystemwaterinventorybalancesatleastevery72hours,whicharecapableofdetectingleakratesofthismagnitude.Inaddition,secondarysystemradiationmonitorsarecapableofdetectingincreasesinsecondarysystemradiationthatwouldresult.fromprimarytosecondaryleaks.Ineithercase,anorderlyreactorshutdownwouldlikelybeperformedbeforesecondarysystemradionuclideinventoriesreachedthelevelsassumedintheaccidentanalysis.Basedontheabovediscussion,wear-induceddegradationinthesteamgeneratorsisnotasafetyconcern.Inaddition,asdiscussedabove,maximumallowabledegradationthatwillsustaintheloadingimposedbynormaloperationandpostulatedaccidentconditionsis63%throughwallpenetration.SincethedegradationinRow49Line85inSG2Bwas47%throughwall,itdidnotexceedthedesignbasis,andstructuralintegritywasnotcompromised.Therefore,thetubewasnotconsideredunserviceableasdescribedinPlantTechnicalSpecificationSection4.4.5.4.a.7.Basedontheabovediscussion,theoperationduringcycles9and10withthedegradationinthetubeatRow49Line85at47%throughwalldidnotadverselyaffectthehealthandsafetyofthepublic.CorrectiveActions1.IncludeinstructionsindataanalysisguidelinesforleadanalystpersonneltoreportconditionstoFPLthatmayindicatethatrepairabledegradationhasnotbeenreportedinpriorexaminations.2.Modifydataanalysisguidelinesforwear-induceddegradationtoincludeinstructionstoscreenthe100kHzdifferentialand100kHzabsolutechannelsinadditiontothe400/100kHzdifferentialmixchannel,andreportflaw-likeindications.3.IncludewearindicationsthatwerereportedinSL2-11inspections,butnotreportedinSL2-10inspections,inthetrainingandtestingofdataanalysispersonnelforfutureoutages.FailedComponentsIdentifiedNoneSimilarEventsLER389-1998-008NRCFORM300A(0.1990) 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}} | }} | ||
Revision as of 11:34, 25 April 2018
| ML17229B080 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/07/1999 |
| From: | MADDEN G R, STALL J A FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L-99-86, LER-99-002, LER-99-2, NUDOCS 9904090149 | |
| Download: ML17229B080 (9) | |
Text
~CATEGORY3yREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9904090149DOC.DATE:99/04/07NOTARIZED:NOFACIL:50-389St.LuciePlant,Unit2,FloridaPowerSLightCo.AUTH.N9ME.AUTHORAFFILIATIONMADDEN,G.R.FloridaPower6LightCo.STALL,J.A.FloridaPower&:LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKET05000389
SUBJECT:
LER99-002-00:on990311,SGECTerrorcausesoperationwithconditionprohibitedbyTS.Causedbydeficienciesindataanalysis'guidelineinstructions.Licenseewillchangedataanalysisguidelinesforleadanalysts.With990407ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENTIDCODE/NAMEPD2-3PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DRCH/HOHBNRR/DRPM/PECBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOOREiWNRCPDRCOPIESLTTRENCL11111'1111,11111111RECIPIENTIDCODE/NAMEGLEAVES,WAEODSPD/RABLECENTNRRDRCHHQMBNRR/DSSA/SPLBRGN2FILE01LMITCOMARSHALLNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL112211111111111111D0NNOTETOALLnRIDS>iRECIPIENTSPLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPZESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR19ENCL19 FloridaPower&LightCompany.6351S.OceanOrive,JensenBeach,FL34957~FPtApril7,1999L-99-8610CFR$50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit2DocketNo.50-389ReportableEvent:1999-002-00DateofEvent:March11,1999SGECTErrorCausesOperationwithaConditionProhibitedbTechnicalSeciftcationsTheattachedLicenseeEventReport1999-002isbeingsubmittedpursuanttotherequirementsof10CFR$50.73toprovidenotificationofthesubjectevent.Verytrulyyours,J.A.StallSiteVicePresidentSt.LucieNuclearPlantJAS/EJW/GRMAttachmentcc:RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LucieNuclearPlant9904090149990407PDRADQCK05000389SPDRanFPLGroupcompany NRCFORM366(6-1996)U.S.NUCLEARREGULATORYCOMMISSIONjLICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDBYOMBNO.3150.0104EXPIRES06/30/2001Estimatedburdenperresponsetocomplywithlhismandatoryinformationcollectionrequest:50hrs.ReportedlessonsloomedareincorporatedIntolhelicensingprocessandfedbacktoIndustry.FonrrardcommentsregardingburdenestimateloIheRecordsManagementBmnch(TAF33),U.S.NuckrarRegulatoryCommission,Washington,)3C205554001~andtothePaperwrxkReductionProioct(31500104j,OfficeofManagementandBudget,Washington,Dc20503.IfanfnfonnalioncollectiondoesnotdispbryacurrentlyvalidOMBcontrolnumber,theNRCmaynolconductorsponsor,andapersonisnotrequiredtorespondlo,IheInformationcollection.FACILITYNAME(1ISt.LucieUnit2DOCKETNUMBER(2)05000389PAGE(3)Page1of6TITLE(4)SGECTErrorCausesOperationwithaConditionProhibitedbyTechnicalSpecificationsEVENTDATE(5MONTHOAYYEARLERNUMBER6lSEQUENTIALREVISIONNUMBERNUMBERREPORTDATE(7)MONTHDAYFACILITYNAMEYEAROTHERFACILITIESINVOLVED(BlOOCKETNUMBER031119991999-002-00,0407FACILITYNAME1999OOCKE'rNUMBEROPERATINGMDDE(9)POWERLEVEL(10)100THISREPORTISSUBMITTEDPURSUANTTOTHEREQ20.2203(a)(2l(v)20.2203(a)(3)(i)20.2201(b)20.2203(sl(1)X50.73(a)(2)(i)50.73(a)(2)(u)20.2203(a)(2)(i)20.2203(a)(2)(ii)20.2203(a)(3)(u)20.2203(a)(4)50.73(a)(2)(iii)50.73(BH2)(iv)UIREMENTSOF10CFR%t(Checkoneormore)(11)50.73(s)(2)(vin)50.73(a)(2)(x)73.71OTHER20.2203(sl(2)(iii)20.2203(a)(2)(iv)50.36(c)(1)50.36(c)(2)50.73(a)(2)(v)50.73(a)(2)(vii)SpecifyinAbstractbeloworInNACForm366ANAMELICENSEECONTACTFORTHISLER(12)TELEPHONENUMBERSneIIereArseCedetGeorgeR.Madden(561}467-7155COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT13)CAUSESYSTEMCOMPONENTMANVFACTVAEAREPORTABLETOEPIXCAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETOEPIXSUPPLEMENTALREPORTEXPECTED(14IYES(I(Yes,completeEXPECTEDSUBMISSIONDATE).evIntaXNoEXPECTEDSUBMISSIONDATE(15)MONTHDAYABSTRACT/limitto1400spaces,/.e.,approximately15single.spacedtypewrittenlines/(16)DuringtheSt.LucieUnit2refuelingoutage11(SL2-11}steamgeneratorinspectioninNovember1998,thetubeatRow49Line85insteamgenerator(SG}2Bwaspluggedduetoawear-inducedindicationthatpenetrated47%throughwall,exceedingtheplugginglimitofTechnicalSpecification4.4.5.4.a.6.Uponreviewofhistoricaldata,itwasdeterminedthatthisindicationwaspresent,butnotidentifiedduringtheSL2-9andSL2-10examinations,andthatthedepthofthei.ndicationwasessentiallyunchangedduringthisperiodofoperation.Therefore,thistubeexceededtheplugginglimit,butremainedinserviceduringoperatingcycles9and10.DetectionandsubsequentpluggingofthistubeindicationresultedfromimprovementsinthedataanalysisandcontrolsimplementedfortheSL2-11inspection.LeadanalystsdidnotinformFPLthatthisindicationwasnotidentifiedduringthepriorexaminations.Themisseddetectionwasidentifiedduringthepostoutagereviewacti.vities.Correctiveactionsinclude:changingdataanalysisguidelinesforleadanalyststoreportconditionstoFPLthatmayindicatearepairabledegradationwasnotreportedinapriorexamination;modifyingdataanalysisguidelinesforwear-induceddegradationtoincludeinstructionstoscreenthe100kHzdifferentialand100kHzabsolutechannelsinadditiontothe400/100kHzdifferenti.almixchannel,andreportflaw-likeindications;andincludingthewearindicationsthatwereidentifiedduringtheSL2-11inspections,butnotreportedinSL2-10inspections,inthetrainingandtestingofdataanalysispersonnel.NACFORM366I6.1996)
NRCFORM366A(8-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)St.LucieUnit2~DOCKETNUMBERI2)05000389LERNUMBERI6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGEI3)Page2of6TEXT(Ifmorespeceisrequired,useadditionelcopiesofNRCFarm366A)I17)EventDescriptionOnMarch11,1999,apostoutagereviewofthesteamgenerator(SG)[EIIS:AB:SG)tubedegradationtrendswasbeingpreparedforthefall1998refuelingoutage(SL2-11)steamgeneratorexaminationreport.Itwasnotedthatawear-inducedindicationinthetubeatRow49Line85ofSG2Bwasreportedas47%throughwallanddidnotshowanyevidenceofgrowthbasedoncomparisontotheSL2-10examinationdata.ThistubewaspluggedduringtheSL2-lloutage.ThisreviewconfirmedthatthisindicationwaspresentintheSL2-10examinationdata,andmeasuredapproximatelythesamedepth,butwasnotreported.Althoughtheleadreviewteam(LRT)analysts(contractors)hadmadethissamedeterminationduringtheSL2-11examination,itwasnotbroughttotheattentionoftheFPLrepresentative.AmoreextensivereviewonMarch12,1999determinedthattheindicationwasalsopresentintheSL2-7,SL2-8andSL2-9examinationdataandwasnotreportedbyeithertheprimaryorsecondaryanalysts(contractor).Thisreviewshowedthattheindicationdidnotexceedtheplugginglimit(40%.throughwall)ofplantTechnicalSpecificationsuntiltheSL2-9andlaterexaminations.IntheSL2-11examination,theindicationwasnotreportedbytheprimaryanalyst(contractor),butwasidentifiedbythesecondaryanalyst(contractor)throughtheuseofacomputerdatascreeningsystem(CDS).TheCDSsystemusespre-establishedscreeningparametersthatarequalifiedtodetectdegradationthatisknownorpostulatedtoexistintheSGs.DuringtheSL2-11examination,theCDSsystemparameterswereenhanced"toscreenforpotentialfree-spancracking,whichhasbeenreportedduringprevious'examinationsintheSt.LucieUnit1(originalSGs),SONGS,andCalvertCliffsSGs.Theenhancedscreeningparametersusedforfree-spancrackingoverlappedthesameregionofthetubebundleinwhichthediagonalsupportwear-inducedindicationsoccur,andresultedindetectionofthewear-inducedindicationthatpreviouslywasnotreported.CauseoftheEventAbarrieranalysiswascompletedtodeterminethecausesthatcontributedtothisevent.ThecausesfornotreportingtheindicationintheSL2-10examinationweredeterminedtobe;1)deficienciesindataanalysisguidelineinstructions,and2)inadequatedataanalysttraining.Inaddition,thedataanalysisguidelinedidnotinstructleadanalysts(contractor)toreportconditionstoFPLthatmayindicatethatarepairabledegradationwasnotreportedinpriorexaminations.Thiswouldprovideearlieridentificationofpotentialproblems.AreviewofindustryqualifiedexaminationtechniquesprovidedthroughEPRIshowsthat,forwear-inducedindications,screeningofthe400/100Khzdifferentialmixchannelisoneofseveralacceptabletechniques.Latitudeisgivenfortheusertospecifyadditionalchannelstobescreenedforconfirmationandtoprovideadditionalinstructions.ThisinformationhasbeensharedwithEPRIfortheirreview.Withtheexceptionoftheaddedinstructionstoscreenthe100Khzdifferentialchannelforfree-spancrackinginSL2-11,thedataanalysisguidelineintheSL2-10andSL2-llexaminationswereidenticalwithrespecttothescreeningandreportingofwear-inducedindications.Theguidelinerequiresthattheindicationappearflaw-likeonthe400/100kHzdifferentialmixchannel,oronthe100kHzabsolutechannel.AreviewofSL2-11datashowsthisindicationmaintainsflaw-likecharacteristicsconsideredtypicalofwear-induceddegradationonthe100Khzdifferentialand100Khzabsolutechannels,butdoesnotmaintaintheminthe400/100KhzdifferentialmixNRCFORM388AI8.1998)
NRCFORM366A(6-I998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)St.LucieUpit2OOCKETNUMBERI2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUM8ERNUMBER1999-002-00PAGEI3)Page3of6TEXTfifmorespaceisrequired,useedditionelcopiesofNRCForm366A)I17)channel.Theapparentlackofflaw-likecharacteristicsinthe400/100Khzdifferentialmixchannelmaybeattributabletoalongerandmoregradualtaperassociatedwithsomediagonalsupportwear-inducedindications.Thiswouldexplainthelackofflaw-likecharacteristicsinthe400/100Khzdifferentialmixchannel,andprovideanexplanationwhytheindicationwasnotreportedduringpreviousexaminations.Theguidelinedoesprovidelatitudetoreportindicationsnotspecificallyaddressedordescribedwithintheguideline(Section15.8),yettheindicationremainedunreported.Xnretrospect,theguidelineshouldrequiredataanalysispersonneltoreportsuspectedwear-inducedindicationsifanyoftheabovechannelsappearflaw-like.Thislogicshouldbeappliedtobothprimaryandsecondaryanalysisreviews.Theindividualanalysts(contractor)thatreviewedthedataforthisindicationhadpreviousSt.LucieUnit2experienceaswellassimilarplantexperience,andarefromreputableorganizations.Furthermore,theirperformancedemonstrationtestresultsdonotindicateaproblemwithdetectionorreportingofwear-inducedindications.Also,dataanalysts(contractor)aretypicallylimitedto8-10hourshiftstoreducefatigue.Nospecificexaminationdate,vendororganization,orworkshiftcanbeidentifiedasasignificantcontributortothisevent.Thissupportstheconclusionthatpotentialinadequaciesexistintheinstructionsprovidedinthedataanalysisguideline,andthesitespecifictrainingandtestingofdataanalysispersonnelforreportingofwear-inducedindications,ratherthaninpersonnelorequipmentrelatedissues.ThecurrentguidelinedoesnotspecificallyprompttheleadreviewanalyststoreportconditionstoFPLthatmayindicatethatarepairabledegradationwasnotpreviouslyreportedinapriorexamination.Althoughthiswouldnothaveeliminatedthefactthattheindicationwasnotreported,itdiddelaytheevaluationofpotentialproblems.Thisagainappearstobeanoversightinthedataanalysisguidelineinstructions.AnalysisofSGexaminationdataisperformedinaccordancewithwritteninstructionsandprotocolthatareprovidedinFPLdataanalysisguidelines.Priortoeachexamination,dataanalysispersonnel(contractor)areindoctrinated,trained,andtestedtodemonstrateproficiencyinapplicationofguidelineinstructions.DataanalysispersonnelarealsorequiredtopassanHPRIstandardizedtrainingandtestingprogramforQualifiedDataAnalyst.ThedataanalysisprocessatFPLincorporatesindependentprimaryandsecondaryanalysesforalldataacquired.Secondaryanalysis.utilizescomputerdatascreening(CDS)methodstoprovideaddedassurancethatallindicationsarereported.Ateamofresolutionanalysts(contractor)dispositionsdifferencesbetweenprimaryandsecondaryanalyses.Leadreviewteams(LRT)(contractor)reviewtheresolutionteamoutputforconsistencyinapplicationofguidelineinstructions,selectindicationsfordiagnosticexaminations,selectin-situtestingcandidatesandprovidefinalinputtothetubeplugginglist.Inadditiontoroutineanalysisasdiscussedabove,reviewsarecompletedtoevaluategrowthtrends,assessdetectionperformance,providedataanalystfeedback,andensurethatallindicationsreportedinapriorexaminationareaddressedinthecurrentexamination.Theleadreviewanalysts(contractor)areinstructedtousehistoricaldatatoevaluatecurrentoutageresults.Thisistypicallyaccomplishedusingthedatasegmentrecall(DSR)functionprovidedintheanalysissoftware,orbyuseofrawdataavailableonopticaldisksorharddrives.DSRisthefirstcourseofNRCFORM3BBAIB.1998)
NRCFORM366A(81998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBERI2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGEI3)Page4of6TEXT(Ifmorespeceisrequired,useedditionalcopiesofNRCForm366AJ(17)actionsinceallindicationsreportedinthepriorexaminationshouldbeavailableinthisformat.Thealternativeistherawdataondisk.TheabsenceofaflawhistoryonDSRforanindicationcouldbeusedtoinitiatefurtherevaluationstodetermineiftheindicationwaspresent,butnotreportedinthepreviousexamination,andifitappearedtoexceedthetube-plugginglimit.Thisinturnshouldalertleadpersonnel(contractor)toinformtheFPLrepresentative.Currentscreeninginstructionsinthedataanalysisguidelinehaveidentifiedmorethan500tubesthatareaffectedbywear-induceddegradation,whichistypicalforthesteamgeneratordesigninstalledatSt.LucieUnit2.Currentinstructions,however,donotaccountforindicationsthatlackflaw-likecharacteristicsinthe400/100kHzdifferentialmixchannel,butmaintainflaw-likecharacteristicsinthe100kHzdifferentialor100kHzabsolutechannels.Areviewofindicationsthathaveremainedunreportedinpriorexaminationsshowsthatonlyoneindication(Row49Line85inSG2B)hasexceededthetube-plugginglimitofPlantTechnicalSpecificationsduringpreviousoperation.Theadditionalscreeningrequirementsimplementedforfree-spancrackingappeartobeeffectiveinreportingthisformofwear-induceddegradation,andshouldberequiredintheanalysisinstructions.Znaddition,dataanalysisguidelinesshouldbemodifiedtoinstructleadanalystpersonneltoreportconditionstoFPLthatmayindicatethatrepairabledegradationisnotbeingreportedinpriorexaminations.Dataanalysttrainingandtestingshouldalsoberevisedtoincludewear-inducedindicationsthathavenotbeenreportedinpriorexaminations.AnalysisoftheEventThiseventisreportableunder10CFR50.73(a)(2)(i)(B)asanyoperationorconditionprohibitedbytheTechnicalSpecifications(TS).TS3.4.5statesthateachsteamgeneratorshallbeoperable.TheapplicableACTIONstatementstatesthatwithoneormoresteamgeneratorsinoperablerestoretheinoperablesteamgeneratortooperablestatuspriortoincreasingT,above200'F.TSSurveillance4.4.5.0statesthateachsteamgeneratorshallbedemonstratedoperablebyperformanceoftherequired'ugmentedinserviceinspectionprogram.TS4.4.5.4.a.6PluggingLimitmeanstheimperfectiondepthatorbeyondwhichthetubeshallberemovedfromserviceandisequalto40%ofthenominaltubewallthickness.TS4.4.5.4.a.7statesthatatubeisunserviceableifitleaksorcontainsadefectlargeenoughtoaffectitsstructuralintegrityintheeventofanoperating-basis-earthquake(OBE),aloss-of-coolant-accident(LOCA),orasteamli.neorfeedwaterlinebreak.Contrarytotheabove,onMarch12,1999,FPLidentifiedthatSG2Boperatedthroughoutoperatingcycle9and10withthetubeatRow45Line85havinga47%throughwallwearindication.SafetySignificanceThesteamgeneratortubesaredescribedinUFSARsection5.4.2.1.3.Thetubesaredesignedtoallowforwallthinningandthegeneratorsaredesignedtominimizethepotentialfordenting.TheUFSARdiscussesconsiderationsforlocalizedcorrosionleadingtotubedegradation,whichisthepredominantdegradationmechanismseenintheindustry.St.LucieUnit2DesignBasisDocument,Volume9,discussesreactorcoolantsystemintegrity.Etalsodiscussesthestructuralintegrityrequirementsforsteamgeneratortubes,andprovidesanassessmentofmaximumallowabletubewallNAGFOAM366A181998)
NRCFORM366A(8.1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBER(2)05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGE(31Page5of6TEXTfifmorospaceisrequired,usoadditionalcopiesofNRCForm368A)(171degradationthatcansustaintheloadingimposedbynormaloperationandpostulatedaccidentconditions.Thisshowsthatamaximumallowabletubewalldegradationof63%iswithinthedesignbasisforthesteamgeneratortubing.MechanicalwearintheUnit2steamgeneratorsisaresultofadesignflawinthefabricationoftheunits.ThedesignflawwasdiscoveredfollowingaprimarytosecondaryleakatanotherplantandatSt.LucieUnit2duringCycle2shortlythereafter.InthetubeleakeventatSt.Lucie2,theleakagewaslimitedtoapproximately20gallonsperday(gpd).Airejectormonitorsreadilydetectedit,andtheunitwasshutdownwithinafewdays.ThehistoricaltubeleaksatSONGSUnit2andSt.LucieUnit2occurredinaregionofthetubebundlethatwasanalyzedtobesusceptibletorapidgrowthrates.PreventativetubepluggingwascompletedatSt.LucieUnit2toremovethesusceptibletubesfromservice~Therefore,itiscurrentlyunlikelythatweardegradationwouldresultinthroughwallpenetrationandprimarytosecondaryleakageinoneortwocyclesofoperation.Extensiveinspectionshavebeencompletedateachrefuelingoutagesincethattime,andtherateofwearhasbeenlow.Afterimplementationofpreventivepluggingmeasures,itwasnotexpectedthattherateofwear-induceddamagewouldresultinathroughwallpenetrationafteroneortwocyclesofoperation.Furthermore,thepotentialeffectsassociatedwithathroughwallpenetrationscenariohavebeenshowntohavenoeffectonsafety.Adesignbasissteamgeneratortuberupture(SGTR)accident,asdescribedinChapter15oftheSt.LucieUFSAR,isdefinedasadouble-endedguillotinebreakofatubethatresultsininitialprimarytosecondaryleakratesinexcessof300GPM.ABB/CEhasperformedprototypicallaboratorytestingtoempiricallydeterminetheleakratefromtubedefectsthatwereintendedtosimulateweardefects,producebytubesupports.Thesetestsshowed"thatinallcases,whenwear-initiateddegradationislesqthanthestructurallimitofthetubing,primarytosecondaryleakagewouldnotbeexpectedtooccurundernormaloperationorpostulatedaccidentconditions.Eveninthemajorityofcaseswhensuchdegradationexceedsthestructurallimit,athroughwallpenetrationofthistypewillresultinaleakratelessthanoneGPM,andwouldnotsuddenlyleakinanuncontrolledmanner.ThesetestresultshavebeenfurthersubstantiatedbytheslowsteadyleakratesthatoccurredduringearlyoperationfromthroughwallpenetrationsintheSONGSUnit2andSt.LucieUnit2steamgenerators.Therefore,'heleakratesthatcouldresultfromweardefectswouldbewithinthecurrentTechnicalSpecificationlimitsoftheunitandwould,therefore,representanoperationalconcernbutnotasafetyconcern.Asaresult,potentialtubedefectsfrommechanicalweararenotconsideredasapossibleinitiatingeventofaSGTRaccidentbut,rather,asapotentialincreaseinthenormalsecondarysystemradionuclideinventorythatisusedasaninitialconditionforotherChapter15accidentanalyses'econdarysystemradionuclideinventoriesassumedintheUFSARChapter15safetyanalysisarebasedononepercentfailedfuelandacontinuousoneGPMprimarytosecondaryleakrate.Asdiscussedabove,themostsevereleakratesassociatedwithtypicalthroughwallwearpenetrationsaretypicallymuchlessthanoneGPM.Inaddition,operationwithonepercentfailedfuelisconsideredhighlyunlikely.Hence,actualsecondarysystemradionuclideinventoriesareexpectedtobemuchlessthanthoseassumedintheaccidentanalysis.Asaresult,theradiologicalconsequencesassociatedwithpostulatedwear-inducedtubeleakagewillbeboundedbythoseaccidentscurrentlydescribedinChapter15oftheUFSAR.NRCFORM309A(9.1998) 0 NRCFORM3BBAIB.I990)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit2DOCKETNUMBER(2I05000389LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-002-00PAGE(3)Page6of6TEXTilfmorospecersrequired,useedditionelcopiesoflVRCForm3S6A)(17)ItshouldalsobenotedthatoperationwithacontinuousoneGPMprimarytosecondaryleakrateisanunrealisticassumption.TheSt.Lucie2TechnicalSpecificationsdonotpermitoperation'ftotalprimarytosecondaryleakageexceedsoneGPMthroughallsteamgenerators,orifleakagefromanyonesteamgeneratorexceeds720gallonsperday(0.5GPM).StLucieperformsprimarysystemwaterinventorybalancesatleastevery72hours,whicharecapableofdetectingleakratesofthismagnitude.Inaddition,secondarysystemradiationmonitorsarecapableofdetectingincreasesinsecondarysystemradiationthatwouldresult.fromprimarytosecondaryleaks.Ineithercase,anorderlyreactorshutdownwouldlikelybeperformedbeforesecondarysystemradionuclideinventoriesreachedthelevelsassumedintheaccidentanalysis.Basedontheabovediscussion,wear-induceddegradationinthesteamgeneratorsisnotasafetyconcern.Inaddition,asdiscussedabove,maximumallowabledegradationthatwillsustaintheloadingimposedbynormaloperationandpostulatedaccidentconditionsis63%throughwallpenetration.SincethedegradationinRow49Line85inSG2Bwas47%throughwall,itdidnotexceedthedesignbasis,andstructuralintegritywasnotcompromised.Therefore,thetubewasnotconsideredunserviceableasdescribedinPlantTechnicalSpecificationSection4.4.5.4.a.7.Basedontheabovediscussion,theoperationduringcycles9and10withthedegradationinthetubeatRow49Line85at47%throughwalldidnotadverselyaffectthehealthandsafetyofthepublic.CorrectiveActions1.IncludeinstructionsindataanalysisguidelinesforleadanalystpersonneltoreportconditionstoFPLthatmayindicatethatrepairabledegradationhasnotbeenreportedinpriorexaminations.2.Modifydataanalysisguidelinesforwear-induceddegradationtoincludeinstructionstoscreenthe100kHzdifferentialand100kHzabsolutechannelsinadditiontothe400/100kHzdifferentialmixchannel,andreportflaw-likeindications.3.IncludewearindicationsthatwerereportedinSL2-11inspections,butnotreportedinSL2-10inspections,inthetrainingandtestingofdataanalysispersonnelforfutureoutages.FailedComponentsIdentifiedNoneSimilarEventsLER389-1998-008NRCFORM300A(0.1990)